The present invention relates to a production process for asymmetric synthesis of cyclopropane-carboxylic acid compound using a chiral copper complex catalyst.
As a process for producing an optically active cyclopropanecarboxylic acid ester derivative, there has been reported a process of using a chiral copper complex catalyst which was prepared by reacting equivalent or excess amount of cupric salt with optically active salicylideneaminoalcohol (JP-B 53-43955, JP-A 50-151842, JP-A 54-73758 and JP-A 59-225194).
However, in the disclosed processes said copper complex required purification by recrystallization or washing with methanol or the like to remove an excessive amount of copper compound.
According to the present invention, a chiral copper complex catalyst composition can be obtained in an industrially advantageously and can be used in an asymmetric cyclopropanation reaction with good reproducibility.
The present invention provides:
1. a chiral copper complex catalyst composition, which is obtained by contacting an optically active N-salicylideneaminoalcohol compound of formula (1): 
xe2x80x83with a mono-valent or di-valent copper compound in an inert solvent,
wherein R1 represents
an alkyl group which may be substituted with a group selected from an alkoxy group, an aralkyloxy group, an aryloxy group, and cycloalkoxy group,
an aralkyl, aryl or cycloalkyl group all of which may be substituted with a group selected from an alkyl group, an alkoxy group, an aralkyloxy group, an aryloxy group, and a cycloalkoxy group,
R2 represent
a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl or phenyl group which may be substituted with a group selected from an alkyl group, an alkoxy group, an aralkyloxy group, an aryloxy group, and a cycloalkoxy group,
X1 and X2 are the same or different and independently represent a hydrogen atom, a halogen atom, a nitro group, an alkyl group, an alkoxy group or a cyano group, and two adjacent X1 and X2 together with the benzene ring to which they are bonded may form a 1-hydroxy-2- or 2-hydroxy-1-naphthyl group, and
the carbon atom denoted by xe2x80x9c*xe2x80x9d is an asymmetric carbon atom having either an S or R configuration, and
the amount of the mono-valent or di-valent copper compound is less than 1 mole per 1 mole of the optically active N-salicylideneaminoalcohol compound of formula (1), and
2. a process for producing an optically active cyclopropane-carboxylic acid ester of formula (2): 
xe2x80x83wherein R3, R4, R5 and R6 are as defined below, and
R7 represents
an alkyl group having 1 to 8 carbon atoms,
a cycloalkyl group which may be optionally substituted with a lower alkyl group,
a benzyl group or phenyl group which may be optionally substituted with a lower alkyl group, a lower alkoxy group or a phenoxy group,
which comprises the steps of:
(a) contacting an optically active N-salicylideneaminoalcohol compound of formula (1): 
xe2x80x83with a mono-valent or di-valent copper compound in an inert solvent,
wherein R1, R2, X1, X2 and xe2x80x9c*xe2x80x9d have the same meanings as defined above, and the amount of the mono-valent or di-valent copper compound is less than 1 mole per 1 mole of the optically active N-salicylideneaminoalcohol compound of formula (1), and
(b) reacting a prochiral olefin of formula (3): 
xe2x80x83wherein R3, R4, R5 and R6 independently represent a hydrogen atom,
a halogen atom,
a (C1-C10)alkyl group which may be substituted with a halogen atom
xe2x80x83or a lower alkoxy group,
a (C4-C8)cycloalkyl group,
an aryl group which may be substituted with a halogen atom, a lower
xe2x80x83alkyl group, or a lower alkoxy group,
R3 and R4, or R5 and R6 may be bonded at their terminals to form an
xe2x80x83alkylene group having 2-4 carbon atoms, and
one of R3, R4, R5 and R6 groups represents an alkenyl group which may be substituted with a halogen atom, an alkoxy group or an alkoxy carbonyl group, of which alkoxy may be substituted with a halogen atom or atoms provided that when R3 and R5 are the same, R4 and R6 are not the same,
xe2x80x83with a diazoacetic acid ester of formula (4):
N2CHCO2R7xe2x80x83xe2x80x83(4)
wherein R7 is the same as defined above, in the presence of a chiral copper complex catalyst composition so produced in step (a).
First, a description will be made to the optically active salicylideneaminoalcohol compound of formula (1) as defined above.
Examples of the alkyl group which may be substituted with a group selected from an alkoxy group, an aralkyloxy group, an aryloxy group and a cycloalkoxy group, represented by R1, include
a (C1-C8)alkyl group (e.g., a methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-pentyl, n-hexyl, n-pentyl, n-octyl, n-nonyl, or n-decyl group) which may be substituted with a group selected from
a (C1-C4)alkoxy group(e.g., a methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, sec-butoxy or t-butoxy group),
a (C7-C11)aralkyloxy group(e.g., a benzyloxy or naphthylmethyloxy group),
a (C6-C11)aryloxy group(e.g., a phenoxy or naphthoxy group),
a (C4-C6)cycloalkoxy group(e.g., a cyclobutyloxy, cyclopentyloxy or cyclohexyloxy group) and the like.
Examples of the aralkyl group, the aryl group and the cycloalkyl group, all of which may be substituted with a group selected from an alkyl group, an alkoxy group, an aralkyloxy group, an aryloxy group and a cycloalkoxy group include
a (C7-C11)aralkyl group(e.g., a benzyl, or naphthylmethyl group),
a (C6-C10)aryl group(e.g., a phenyl, or naphthyl group),
a (C4-C6)cycloalkyl group(e.g., a cyclobutyl, cyclopentyl, or cyclohexyl group), all of which may be substituted with
the (C1-C8)alkyl, (C7-C11)aralkyloxy, (C6-C11)aryloxy and (C4-C6)cycloalkoxy group as specified above and a (C1-C8)alkoxy group(e.g, a methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, sec-butoxy, t-butoxy, n-pentoxy, n-hexyloxy, n-pentyloxy or n-octyloxy group).
The alkyl group represented by R2 include said (C1-C8)alkyl group as above. The cycloalkyl group represented by R2 include said (C4-C6)cycloalkyl group as above.
The aralkyl or phenyl group which may be substituted with a group elected from an alkyl group, an alkoxy group, an aralkyloxy group, an aryloxy group and a cycloalkoxy group represented by R2 include the same meanings as defined above for the groups represented by R1.
The substituent group X1 and X2 of the salicylideneaminoalcohol compound of formula (1) will be explained below.
Examples of the halogen atom represented by X1 and X2 include a fluorine atom, a chlorine atom and a bromine atom.
Examples of the alkyl group include a (C1-C8) alkyl group such as a methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and the like.
Examples of the alkoxy group include the same (C1-C4)alkoxy group as defined above in the alkoxy group for R1.
In salicylideneaminoalcohol compound of formula (1), preferred are
a salicylideneaminoalcohol compound (1) in which X1 represents a bromine atom and X2 is a hydrogen atom or a bromine atom,
a salicylideneaminoalcohol compound (1) in which X1 represents a nitro group and X2 is a hydrogen atom, a methyl group or a methoxy group,
a salicylideneaminoalcohol compound (1) in which X1 represents a chlorine atom and X2 is a chlorine atom, and
a salicylideneaminoalcohol compound (1) in which X1 is a hydrogen atom and X2 is a fluorine atom.
More preferred are
a salicylideneaminoalcohol compound (1) in which X1 represents a nitro group or a bromine atom and X2 is a hydrogen atom,
a salicylideneaminoalcohol compound (1) in which X1 represents a chlorine atom and X2 is a chlorine atom, and
a salicylideneaminoalcohol compound (1) in which X1 is a hydrogen atom and X2 is a fluorine atom.
Among the optically active salicylideneaminoalcohol compound of formula (1), R1 is preferably an alkyl group having 1 to 6 carbon atoms, an aralkyl, an aryl group, and R2 is preferably an alkyl group (e.g. lower alkyl groups having 1 to 6 carbon atoms), an aralkyl group (e.g., a benzyl group), an aryl group (e.g., a phenyl group, a 2-methoxyphenyl group, a 2-tert-butoxy-5-tert-butylphenyl group or a 2-octyloxy-5-tert-butylphenyl group).
Specific examples the optically active salicylideneaminoalcohol compound of formula (1) include optically active
N-salicyliden-2-amino-1,1-diphenyl-1-propanol,
N-salicyliden-2-amino-1,1-di(2-methoxyphenyl)-1-propanol,
N-salicyliden-2-amino-1,1-di(2-isopropoxyphenyl)-1-propanol,
N-salicyliden-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-1-propanol,
N-salicyliden-2-amino-1,1-diphenyl-3-phenyl-1-propanol,
N-salicyliden-2-amino-1,1-di(2-methoxyphenyl)-3-phenyl-1-propanol,
N-salicyliden-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol,
N-salicyliden-2-amino-1,1-di(2-butoxy-6-t-butylphenyl)-3-phenyl-1-propanol,
N-salicyliden-2-amino-1,1-di(2-methoxyphenyl)-3-phenyl-1-butanol,
N-(3-fluorosalicyliden)-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-di(2-octyloxy-5-t-butylphenyl)-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-3-phenyl-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-di(2-methoxyphenyl)-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-diphenyl-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-di(2-benzyloxy-5-methylphenyl)-3-(4-iso-propoxyphenyl)-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-diphenyl-3-phenyl-1-propanol,
N-(3-fluorosalicyliden)-2-amino-1,1-di(2-methoxyphenyl)-3-methyl-1-butanol,
N-(3-fluorosalicyliden)-2-amino-3-phenyl-1-propanol,
N-(3,5-dichlorosalicylidene)-2-amino-1,1-diphenylpropanol,
N-(3,5-dichlorosalicylidene)-2-amino-1,1-di-(2-methoxyphenyl)propanol
N-(3,5-dichlorosalicylidene)-2-amino-1,1-di(5-tert-butyl-2-tert-butoxyphenyl)-3-phenyl-1-propanol,
N-(3,5-dichlorosalicylidene)-2-amino-1,1-di-(5-tert-butyl-2-octyloxyphenyl)-propanol
N-(5-bromosalicyliden)-2-amino-1,1-diphenyl-1-propanol,
N-(5-bromosalicyliden)-2-amino-1,1-di(2-methoxyphenyl)-1-propanol,
N-(3,5-dibromosalicyliden)-2-amino-1,1-diphenyl-1-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-diphenyl-1-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-diphenyl-3-phenyl-1-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-3-phenyl-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-di(2-benzyloxy-5-methylphenyl)-3-(4-iso-propoxyphenyl)-1-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-di(2-methoxyphenyl)-1-propanol,
N-(5-nitrosalicyliden)-2-amino -1,1-di(2-t-butyl-4-methylphenyl)-3-phenyl-1-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-di(2-butoxy-5-t-butylphenyl )-1-propanol,
N-(5-nitrosalicyliden)-2-amino-1,1-di(2-methoxyphenyl)-3-methyl-1-butanol,
N-(5-nitrosalicylidene)-2-amino-1,1-di-(5-tert-butyl-2-octyoxyphenyl)-1-propanol,
N-(5-nitrosalicylidene)-2-amino-1,1-di(5-tert-butyl-2-tert-butoxyphenyl)-3-phenyl-1-propanol,
N-(3-methoxy-5-nitrosalicyliden)-2-amino-1,1-di(2-butoxy-5-t-butylphenyl )-1-propanol,
N-(3-methoxy-5-nitrosalicyliden)-2-amino-1,1-di(2-methoxyphenyl )-1-propanol,
N-(3-methoxy-5-nitrosalicyliden)-2-amino-1,1-diphenyl -1-propanol,
N-(3-t-butylsalicyliden)-2-amino-1,1-diphenyl-1-propanol,
N-(3,5-di-t-butylsalicyliden)-2-amino-1,1-di(2-methoxyphenyl)-1-propanol, and the like. Said optically active compounds may have either an S configuration or R configuration with respect to the carbon atom denoted by xe2x80x9c*xe2x80x9d in the formula above.
The salicylidenaminoalcohol of formula (1) is usually contacted with a mono-valent or di-valent copper compound to produce a chiral copper complex in an inert solvent.
Examples of the mono-valent or di-valent copper compound include
a copper salt of an organic carboxylic acid having 2 to 15 carbon atoms such as copper acetate, copper naphthenate, copper octanoate and the like, and a copper salt such as copper chloride, copper bromide, copper nitrate, copper sulfate, copper methanesulfonte, copper trifluoromethanesulfonate, copper cyanate, copper carbonate and copper oxide, and a mixture thereof.
Examples of the inert solvent include a hydrocarbon such as hexane, heptane, cyclohexane or the like, an ester such as methyl acetate, ethyl acetate, ethyl propionate or the like, a ketone such as acetone, methyl ethyl ketone or the like, a halogenated hydrocarbon such as butyl chloride, dichloroethane, chloroform, carbon tetrachloride or the like, and an aromatic hydrocarbon such as toluene, xylene or the like. The mixture of solvent described above can be also used. An amount thereof to be used is not particularly limited. Prochiral olefins of formula (3) to be used in the next cyclopropanation step may also be used as a solvent.
An amount of the copper compound to be used is less than 1 mole, usually 0.2 to 0.95 mole, preferably 0.4 to 0.94 mole per mol of the optically active salicylideneaminoalcohol compound of formula (1). The reaction temperature is usually room temperature to the boiling point of the solvent used, or typically 10 to 100xc2x0 C.
The reaction mixture, which is the present chiral copper complex catalyst composition, can be used as it is for the asymmetric synthesis, or it may be concentrated to a suitable concentration, if necessary. The chiral copper catalyst composition thus obtained usually contains 0.1 to 30 (wt) % of the chiral copper complex which is derived from the slicylideneaminoalcohol compound of formula (1) and the copper compound, and the inert solvent. It can also be used after the isolation by removing the solvent.
Alternatively, the resulting reaction mixture may be further contacted-with a base, if necessary.
Examples of the base include
an alkali metal alcoholate such as sodium methylate and sodium ethylate, which can be used as they are as powders or as a solution in alcohol such as methanol, ethanol or the like,
alkali metal hydroxide such as sodium hydroxide, potassium hydroxide or the like,
alkali metal carbonate or bicarbonate such as sodium carbonate, sodium bicarbonate and the like. These are usually used as an aqueous solution.
The amount of the base to be used is usually 0.1-8 moles, preferably around 0.5-3 moles per mole of the copper compound.
Although the resulting reaction mixture can be used as it is without removing a salt produced by neutralization of them (for example, sodium acetate in the case of using copper acetate, sodium naphthenate in the case of using copper naphthenate), it is preferably used after removing the salt by washing with water. In this case, the catalyst may be used after being dehydrated.
Thus obtained chiral copper complex catalyst composition in a solution form, of which concentration is usually within the range of the concentration as described above, optionally adjusted by concentration or addition of an appropriate solvent, can be used in the cyclopropanation reaction, hence a purifying step is not particularly necessary. Although the product can be isolated by removing the solvent, the solution is usually used as it is and, therefore, the present catalyst composition is suitably used in a continuous reaction process because of ready feeding of catalyst.
Although the structure of an asymmetric copper complex catalyst obtained herein is not always clearly established, it shows practically good activity for an industrial production process.
Next, a description will be made to the step of producing optically active cyclopropane-carboxylic acid ester of formula (2) as defined above, which step comprising reacting a prochiral olefin of formula (3) with a diazoacetic acid ester of formula (4) in the presence of a chiral copper complex catalyst composition so produced.
R3, R4, R5 or R6 of the prochiral olefin of formula (3) will be explained below.
Examples of the alkyl group which may be substituted with a halogen atom or an alkoxy group include
a linear or branched alkyl group having 1 to 10 carbon atoms such as a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, or n-decyl group,
an alkyl group substituted with a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and the like a haloalkyl group such as a chloromethyl, dichloromethyl, trichloromethyl, difluoromethyl, trifluoromethyl, 2,2,2-trichloroethyl group or the like,
an alkyl group substituted with an alkoxy group such as a methoxy, ethoxy, n-propoxy, i-propoxy group or the like.
Examples of the alkylene group formed by R3 and R4, or R5 and R6 include an alkylene group having 2 to 4 carbon atoms such as dimethylnene, trimethylene, or tetramethylene group.
Examples of the alkenyl group which may be substituted with a halogen atom, an alkoxy group or an alkoxy carbonyl group, of which alkoxy may be substituted with a halogen atom or atoms, represented by R3, R4, R5 include
a linear or branched alkenyl groups having 1 to 10 carbon atoms such as an ethenyl, propenyl, 2-methylpropenyl, 1-butenyl, 2-butenyl, or hexenyl group,
a haloalkenyl group, which is the above-described alkenyl group substituted with the above-described halogen atom or atoms, such as a chloroethenyl group, a chloropropenyl group, 2,2-dichloroethenyl group, 2,2-difluoroethenyl group or the like,
an alkoxy(C1-C3)carbonyl substituted alkenyl group such as 2-methoxycarbonyl-2-methylethenyl group, 2-(1,1,1,3,3,3-hexafluoroisopropoxycarbonyl)-1-methylethenyl group or the like.
Specific examples of the prochiral olefin (3) include propene, 1-butene, isobutylene, 1-pentene, 1-hexene, 1-octene, 4-chloro-1-butene, 2-pentene, 2-heptene, 2-methyl-2-butene, 2,5-dimethyl-2,4-hexadiene, 2-chloro-5-methyl-2,4-hexadiene, 2-fluoro-5-methyl-2,4-hexadiene, 1,1,1-trifluoro-5-methyl-2,4-hexadiene, 2-methoxycarbonyl-5-methyl-2,4-hexadiene, 1,1-difluoro-4-methyl-1,3-pentadiene, 1,1-dichloro-4-methyl-1,3-pentadiene, 2-methyl-2,4-hexadiene, 2,3-dimethyl-2-pentene, 1,1,1-trichloro-4-methyl-3-pentene and the like. 1,1-dibromo-4-methyl-1,3-pentadiene, 1-chloro-1-fluoro-4-methyl-1,3-pentadiene, 1-fluoro-1-bromo-4-methyl-1,3-pentadiene, 2-(1,1,1,3,3,3-hexafluoroisopropoxycarbonyl)-5-methyl-2,4-hexadiene, 1-methoxy-4-methyl-1,3-pentadiene, 1-ethoxy-4-methyl-1,3-pentadiene, 1-propoxy-4-methyl-1,3-pentadiene, 1-fluoro-1-methoxy-4-methyl-1,3-pentadiene, 1-fluoro-1-ethoxy-4-methyl-1,3-pentadiene, 1-fluoro-1-propoxy-4-methyl-1,3-pentadiene, 1,1,1-tribromo-4-methyl-3-pentene, 2-bromo-2,2-dimethyl-4-hexene, 2-chloro-2,5-dimethyl-4-hexene, 1-methoxy-2-methyl-1-propene, 1-ethoxy-2-methyl-1-propene, 1-propoxy-2-methyl-1-propene, 1-methoxy-8-methyl-2-butene, 1-ethoxy-3-methyl-2-butene, 1-propoxy-3-methyl-2butene, 1,1-dimethoxy-3-methyl-2-butene, 1,1-diethoxy-3-methyl-2-butene, isopropylidenecyclopropane, isopropylidenecyclobutane, isopropylidenecyclopentane and the like.
Examples of the alkyl group having 1 to 8 carbon atoms represented by R7 in formula (4) include
a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, a n-hexyl group, a n-octyl group and the like.
Examples of the cycloalkyl group which may be optionally substituted with a lower alkyl group include a cyclohexyl group, a 1-menthyl group, a d-menthyl group.
Examples of the phenyl or benzyl group which may be optionally substituted with a lower alkyl group, a lower alkoxy group or a phenoxy group represented by R7 in formula (4) include a phenyl group, a 2-methylphenyl group, a 3,5-dimethylphenyl group, a 4-methyl-2,6-di-tert-butylphenyl group, a 2-methoxyphenyl group, a 3,5-dimethoxyphenyl group, a benzyl group, a 3-phenoxybenzyl group and the like.
Examples of the lower alkyl group which may be present on the cycloalkyl group or on the phenyl group include a (C1-C4)alkyl group such as a methyl group, an ethyl group, a n-propyl group, an i-propyl group, a n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group.
Examples of the lower alkoxy group which may be present on the phenyl group include a (C1-C4)alkoxyl group such as a methoxy group, an ethoxy group, a n-propoxy group, an i-propoxy group, a n-butoxy group, an i-butoxy group, a sec-butoxy group, and a t-butoxy group.
Preferred are a (C1-C6)alkyl group, a cyclohexyl group, a 1-menthyl group, a d-menthyl group, a phenyl group, a 2-methylphenyl group, a 3,5-dimethylphenyl group, a 4-methyl-2,6-di-tert-butylphenyl group, a 2-methoxyphenyl group, a 3,5-dimethoxyphenyl group and a 3-phenoxybenzyl group.
Specific examples of the diazoacetic acid ester of formula (4) include ethyl diazoacetate, n-propyl diazoacetate, tert-butyl diazoacetate, phenyl diazoacetate, 1-menthyl diazoacetate, cyclohexyl diazoacetate and the like.
Said diazoacetic esters of formula (4) is commercially available or may be prepared by the known method such as a method of reacting corresponding amino acid esters with a diazotizing agent such as sodium nitrite and mineral acids may be used.
The reaction of prochiral olefin of formula (3) with diazoacetic esters of formula (4) in the presence of the prepared copper complex catalyst composition is usually performed by adding the diazoacetic ester of formula (4) to a mixture of the copper complex catalyst composition and the prochiral olefin (3) and optionally in a solvent. The present reaction may be performed in the presence of a reducing agent such as phenylhydrazine or the like.
An amount of prochiral olefins of formula (3) to be used is usually 1 mole or more per mol of the diazoacetic esters of formula (4). The upper limit thereof is not particularly limited and, for example, a large excess amount may be used so as to serve as a reaction solvent.
An amount of the copper complex catalyst to be used is usually 0.001 to 1 mole %, preferably 0.002 to 0.5 mole % in terms of copper relative to diazoacetic esters of formula (4).
Examples of the solvent to be used include a halogenated hydrocarbon such as 1,2-dihloroethane, chloroform, carbon tetrachloride or the like,
an aliphatic hydrocarbon such as hexane, heptane, cyclohexane and the like,
an aromatic hydrocarbon such as benzene, toluene, xylene and the like,
an ester such as methyl acetate, ethyl acetate and the like, and a mixture thereof. Alternatively, prochiral olefin (3) may be used as a solvent.
An amount of the solvent to be used is usually 2 to 50 parts by weight, preferably 3 to 30 parts by weight per 1 part by weight of the diazoacetic ester (4).
A reaction temperature is usually 5 to 150xc2x0 C., preferably 10 to 120xc2x0 C. In addition, the reaction is usually performed under an inert gas atmosphere such as a nitrogen gas or the like.
After completion of the reaction, the optically active cyclopropanecarboxylic acid ester derivative of formula (2) can be separated by distillation or the like, which may be subjected to ester hydrolysis or the like, or may be further purified, for example, by distillation, column chromatography or the like, if necessary.
Examples of the optically active cyclopropanecarboxylic acid esters of formula (2) include optically active
methyl 2-methylcyclopropanecarboxylate,
ethyl 2-methylcyclopropanecarboxylate,
n-propyl 2-methylcyclopropanecarboxylate,
isopropyl 2-methylcyclopropanecarboxylate,
isobutyl 2-methylcyclopropanecarboxylate,
tert-butyl 2-methylcyclopropanecarboxylate,
cyclohexyl 2-methylcyclopropanecarboxylate,
menthyl 2-methylcyclopropanecarboxylate,
4-methyl-2,6-di-tert-butylphenyl 2-methylcyclopropanecarboxylate,
methyl 2,2-dimethylcyclopropanecarboxylate,
ethyl 2,2-dimethylcyclopropanecarboxylate,
n-propyl 2,2-dimethylcyclopropanecarboxylate,
isopropyl 2,2-dimethylcyclopropanecarboxylate,
isobutyl 2,2-dimethylcyclopropanecarboxylate,
tert-butyl 2,2-dimethylcyclopropanecarboxylate,
cyclohexyl, 2,2-dimethylcyclopropanecarboxylate,
menthyl 2,2-dimethylcyclopropanecarboxylate,
methyl 2,2,3-trimethylcyclopropanecarboxylate,
ethyl 2,2,3-trimethylcyclopropanecarboxylate,
n-propyl 2,2,3-trimethylcyclopropanecarboxylate,
isopropyl 2,2,3-trimethylcyclopropanecarboxylate,
isobutyl 2,2,3-trimethylcyclopropanecarboxylate,
tert-butyl 2,2,3-trimethylcyclopropanecarboxylate,
cyclohexyl, 2,2,3-trimethylcyclopropanecarboxylate,
menthyl 2,2,3-trimethylcyclopropanecarboxylate,
4-methyl-2,6-di-tert-butylphenyl 2,2-dimethylcyclopropanecarboxylate,
methyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
ethyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
n-propyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
isopropyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
isobutyl 2,2-dimethyl-3-(3-methyl-1-propenyl)cyclopropanecarboxylate,
tert-butyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
cyclohexyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
menthyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
(4-methyl-2,6-di-tert-butylphenyl)
2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropanecarboxylate,
methyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
ethyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
n-propyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
isopropyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
isobutyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
tert-butyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
cyclohexyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
menthyl 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
(4-methyl-2,6-di-tert-butylphenyl) 2,2-dimethyl-3-(2,2-dichloro-1-ethenyl)cyclopropanecarboxylate,
methyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
ethyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
n-propyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
isopropyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
isobutyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
tert-butyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
cyclohexyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
menthyl 2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate,
4-methyl-2,6-di-tert-butylphenyl
2,2-dimethyl-3-(2,2,2-trichloroethyl)cyclopropanecarboxylate and the like.
The optically active salicylideneaminoalcohol compound of formula (1) contained in the residue after isolating the optically active cyclopropanecarboxylic acid ester derivative of formula (2) can be recovered by subjecting the residue to crystallization treatment, column chromatography or the like.
The optically active salicylideneaminoalcohol compound of formula (1) can be obtained, for example, by reacting an optically active amino alcohol of formula (5): 
wherein R1 and R2 have the same meaning s as defined above, with a salicylaldehyde derivative of formula (6): 
wherein X1 and X2 are the same as defined above.
The optically active amino alcohol compound of formula (5) to be used in this process include those having R1 and R2 groups as specified above and specific examples thereof include optically active
2-amino-1,1-diphenyl-1-propanol,
2-amino-1,1-di(2-methoxyphenyl)-1-propanol,
2-amino-1,1-di(2-isopropoxyphenyl)-1-propanol,
2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-1-propanol,
2-amino-1,1-diphenyl-3-phenyl-1-propanol,
2-amino-1,1-di(2-methoxyphenyl)-3-phenyl-1-propanol,
2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol,
2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-3-phenyl-1-propanol,
2-amino-1,1-di(2-methoxyphenyl)-3-phenyl-1-butanol,
2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-1-propanol,
2-amino-1,1-di(2-octyloxy-5-t-butylphenyl)- -propanol,
2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-3-phenyl-1-propanol,
2-amino-1,1-di(2-methoxyphenyl)-1-propanol,
2-amino-1,1-di(2-benzyloxy-5-methylphenyl)-3-(4-isopropoxyphenyl)-1-propanol,
2-amino-1,1-di(2-methoxyphenyl)-3-methyl-1-butanol,
2-amino-3-phenyl-1-propanol,
2-amino-1,1-di(2-t-butyl-4-methylphenyl)-3-phenyl-1-propanol,
2-amino-1,1-di(4-t-butylphenyl)-1-propanol,
2-amino-1,1-di(2-methoxyphenyl)-3-methyl-1-propanol and the like.
The reaction of the optically active amino alcohol (5) with the salicylaldehyde derivative (6) is usually conducted at room temperature to the boiling point of the solvent used.
Said reaction is usually conducted by contacting the optically active amino alcohol (5) with the slicylaldehyde derivative (6) in an organic solvent, examples of which include an aromatic hydrocarbon solvent such as toluene, xylene or the like, a halogenated hydrocarbon solvent such as chlorobenzene, dichloroethane or the like and an alcohol solvent such as methanol, ethanol or the like and a mixture thereof An amount thereof to be used is not particularly limited.
An amount of the slicylaldehyde derivative to be used is usually 0.8 to 1.5 moles, preferably 0.9 to 1.2 moles per mol of the optically active amino alcohol of formula (5). The reaction may be conducted under dehydrating water which is produced during the reaction.